The case study presented in this paper focuses on the so-called \“Vela roof”. This
roof is part of a larger project under construction in Bologna. The focus of the
study concerns the use of on-site renewable climate (energy) resources for
thermal comfort with special attention given to passive cooling and heating. The
very first conceptual design developed by the architectural office is assumed as a
starting point for the inclusion of performance criteria at this stage in the process,
taking into account a large chain of dependencies that need to be integrated in the
design process. Due to extremely low wind speeds on-site, early evaluations
pointed out how wind should be caught in order to provide some cooling effect;
secondly, side openings at the wrong location on the roof would contribute to a
green house effect more than to a passive cooling effect. As a result, in the
preliminary design of the roof uncomfortable conditions were highly expected
under the whole roof in the summer, with an even higher critical level in the
space between the lower buildings’ roof and the Vela. Two main issues of the
Vela are therefore highlighted especially related to the improvement of the
existing design (configuration and shape). On one hand, in the preliminary
design the overheated air was going to be kept at the top enclosed spaces without
being passively extracted. On the other hand, the system of side openings could
be related better to the local wind behaviour. The latter has been analyzed and
digitally simulated and the first results are presented in this paper. Integration of
these main issues in larger strategies was also investigated, considering both
active solar technologies and passive systems for heating and cooling.
Keywords: on-site renewable energy resources, urban space related comfort.